Copper (Cu) and zinc (Zn) do not have the same number of valence electrons.
Copper, with an atomic number of 29, belongs to Group 11 of the periodic table, also known as the transition metals. The electron configuration of copper is [Ar] 3d^10 4s^1. In this configuration, copper has one valence electron in the 4s orbital.
Zinc, on the other hand, has an atomic number of 30 and belongs to Group 12 of the periodic table. Its electron configuration is [Ar] 3d^10 4s^2. In this configuration, zinc has two valence electrons, one in the 4s orbital and ten in the 3d orbital.
Although both copper and zinc have the same electron configuration in the 3d orbital (3d^10), their valence electron count is different. Copper has a single valence electron in the 4s orbital, while zinc has two valence electrons in the 4s orbital and ten in the 3d orbital.
The number of valence electrons determines an element's chemical properties and reactivity. In the case of copper, the presence of a single valence electron in the 4s orbital makes it more likely to undergo oxidation and participate in chemical reactions. Zinc, with its filled 3d orbital and two valence electrons in the 4s orbital, has a tendency to lose those two electrons to achieve a stable electron configuration, resulting in a +2 oxidation state.
Therefore, copper and zinc have different numbers of valence electrons, which influences their chemical behavior and reactivity.